Skip to content

Commit

Permalink
ppc/spapr: Add support for implement support for H_SCM_HEALTH
Browse files Browse the repository at this point in the history
Add support for H_SCM_HEALTH hcall described at [1] for spapr
nvdimms. This enables guest to detect the 'unarmed' status of a
specific spapr nvdimm identified by its DRC and if its unarmed, mark
the region backed by the nvdimm as read-only.

The patch adds h_scm_health() to handle the H_SCM_HEALTH hcall which
returns two 64-bit bitmaps (health bitmap, health bitmap mask) derived
from 'struct nvdimm->unarmed' member.

Linux kernel side changes to enable handling of 'unarmed' nvdimms for
ppc64 are proposed at [2].

References:
[1] "Hypercall Op-codes (hcalls)"
    https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/powerpc/papr_hcalls.rst#n220
[2] "powerpc/papr_scm: Mark nvdimm as unarmed if needed during probe"
    https://lore.kernel.org/linux-nvdimm/[email protected]/

Signed-off-by: Vaibhav Jain <[email protected]>
Message-Id: <[email protected]>
Reviewed-by: Greg Kurz <[email protected]>
Signed-off-by: David Gibson <[email protected]>
  • Loading branch information
vaibhav92 authored and dgibson committed May 4, 2021
1 parent 4b98e72 commit 53d7d7e
Show file tree
Hide file tree
Showing 2 changed files with 38 additions and 1 deletion.
36 changes: 36 additions & 0 deletions hw/ppc/spapr_nvdimm.c
Original file line number Diff line number Diff line change
Expand Up @@ -31,6 +31,10 @@
#include "qemu/range.h"
#include "hw/ppc/spapr_numa.h"

/* DIMM health bitmap bitmap indicators. Taken from kernel's papr_scm.c */
/* SCM device is unable to persist memory contents */
#define PAPR_PMEM_UNARMED PPC_BIT(0)

bool spapr_nvdimm_validate(HotplugHandler *hotplug_dev, NVDIMMDevice *nvdimm,
uint64_t size, Error **errp)
{
Expand Down Expand Up @@ -467,6 +471,37 @@ static target_ulong h_scm_unbind_all(PowerPCCPU *cpu, SpaprMachineState *spapr,
return H_SUCCESS;
}

static target_ulong h_scm_health(PowerPCCPU *cpu, SpaprMachineState *spapr,
target_ulong opcode, target_ulong *args)
{

NVDIMMDevice *nvdimm;
uint64_t hbitmap = 0;
uint32_t drc_index = args[0];
SpaprDrc *drc = spapr_drc_by_index(drc_index);
const uint64_t hbitmap_mask = PAPR_PMEM_UNARMED;


/* Ensure that the drc is valid & is valid PMEM dimm and is plugged in */
if (!drc || !drc->dev ||
spapr_drc_type(drc) != SPAPR_DR_CONNECTOR_TYPE_PMEM) {
return H_PARAMETER;
}

nvdimm = NVDIMM(drc->dev);

/* Update if the nvdimm is unarmed and send its status via health bitmaps */
if (object_property_get_bool(OBJECT(nvdimm), NVDIMM_UNARMED_PROP, NULL)) {
hbitmap |= PAPR_PMEM_UNARMED;
}

/* Update the out args with health bitmap/mask */
args[0] = hbitmap;
args[1] = hbitmap_mask;

return H_SUCCESS;
}

static void spapr_scm_register_types(void)
{
/* qemu/scm specific hcalls */
Expand All @@ -475,6 +510,7 @@ static void spapr_scm_register_types(void)
spapr_register_hypercall(H_SCM_BIND_MEM, h_scm_bind_mem);
spapr_register_hypercall(H_SCM_UNBIND_MEM, h_scm_unbind_mem);
spapr_register_hypercall(H_SCM_UNBIND_ALL, h_scm_unbind_all);
spapr_register_hypercall(H_SCM_HEALTH, h_scm_health);
}

type_init(spapr_scm_register_types)
3 changes: 2 additions & 1 deletion include/hw/ppc/spapr.h
Original file line number Diff line number Diff line change
Expand Up @@ -538,8 +538,9 @@ struct SpaprMachineState {
#define H_SCM_BIND_MEM 0x3EC
#define H_SCM_UNBIND_MEM 0x3F0
#define H_SCM_UNBIND_ALL 0x3FC
#define H_SCM_HEALTH 0x400

#define MAX_HCALL_OPCODE H_SCM_UNBIND_ALL
#define MAX_HCALL_OPCODE H_SCM_HEALTH

/* The hcalls above are standardized in PAPR and implemented by pHyp
* as well.
Expand Down

0 comments on commit 53d7d7e

Please sign in to comment.